Delete old duckdb index files

default/train/index.duckdb

@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:63d590edac0b39ae32e3bd1bff901e2cb6a17e7f1c7749009645cc4109d0dcef
-size 133967872

default/train/partial-index.duckdb

@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:7c87dee47b700218a3049e0b2d2bf81f640694121b09931a2a834c72465fd1ca
-size 4483198976